Finally, some protection for my Raspberry Pi! The PCB fit is slightly loose, but that was quickly sorted with the application of a couple of spots of hot glue in the corners.
Unfortunately, the case is a couple of mm too small to fit the main board from the Pico Projector inside, so I won’t be butchering that into the case with the Pi as yet. What is required is an interface to the display engine from the Pi’s DSI interface.
The pi all boxed. up. The only thing that this case would now require is a lightpipe to direct the LED’s light to the openings in the case, as they are very difficult to see at present.
Here’s the teardown of the projector itself! On the right is the info label from the projector, which covers the flex ribbon to the VGA/composite input board below.
This unit is held together with Allen screws, but is easy to get apart.
Here’s the insides of the projector, with just the top cover removed. The main board can be seen under the shielding can, the Micro HDMI connector is on the left & the MicroUSB connection is on the right. The USB connection is solely for charging the battery & provides no data interface to the unit.
On top of the main board is the shield can covering the PicoP Display Engine driver board, this shield was soldered on so no peek inside unfortunately!
The laser module itself is in the front of the unit, the laser assemblies are closest to the camera, on the left is the Direct Doubled Green module, in the centre is the blue diode, and the red diode on the right. Inside the module itself is an arrangement of mirrors & beamsplitters, used to combine the RGB beams from the lasers into a single beam to create any colour in the spectrum.
Here is the module innards revealed, the laser mounts are at the top of the screen, the green module is still mounted on the base casting.
The three dichroic mirrors in the frame do the beam combining, which is then bounced onto the mirror on the far left of the frame, down below the MEMs. From there a final mirror directs the light onto the MEMs scanning mirror before it leaves through the output window.
A trio of photodiodes caters for beam brightness control & colour control, these are located behind the last dichroic turning mirror in the centre of the picture.
This is inside the green laser module, showing the complexity of the device. This laser module is about the size of a UK 5p coin!
And here on the left is the module components labelled.
Here is the main PCB, with the unit’s main ARM CPU on the right, manufactured by ST.
User buttons are along the sides.
Other side of the main board, with ICs that handle video input from the HDMI connector, battery charging via the USB port & various other management.
Above is the image projected from the Pi, on the default login screen. Distance from the projector is approx 10 feet.
State of the art projector mount, fashioned from several cable ties. HDMI cable is plugged into the right hand side of the projector.
Unfortunately the projector cannot handle audio on the HDMI connector, the 3.5mm headphone jack on the projector is for splitting audio out of the iDevice connection only, and does not make the HDMI audio stream available.
The Raspberry Pi, hosting a USB keyboard, & USB powered speakers. Running the standard Debian release, on a 16GB card, with omxplayer installed for media functions.